I bought this bike a week ago. Not sure when I lost it but the vent tube on gas cap is missing. Not sure what happened to it because it was on there when I bought it. I've think I've ridden a couple of times without it. Do I need to buy a new gas cap now? Also what's the rubber gasket that comes with it.? Changed the oil today.I noticed there was no spring in the oil filter. Isn't there suppose to be a spring? Also, it's a SS filter so after I clean it do I have to wait for it dry before I put it back in? (no compressed air to dry it with) ?